DE960281C - Process for the preparation of 5-chloro-1, 2, 4-thiodiazoles - Google Patents

Description

Process for the preparation of 5-chloro-1, 2, 4-thiodiazoles E. Söderbäck (Ann. 465, 184 [19a8] and Svensk. kem. Tid. 56, 2o7 [194.q]) received on exposure from hydrogen chloride to dirhodane a di- (5-chlori, a, 4-thiodiazolyl-3) disulfide: which could be reduced to the corresponding mercapto compound and converted into 3-rhodano-5-chloro-1,2,4-thiodiazole. Other halogen compounds of the ring system mentioned have not yet been described (cf. LL B ambas in Weissberger: The Chemistry of Heterocyclic Compounds, Interscience Publishers, New York, Vol. 4 [19521). It has been found that 5-chloro-i, 2, 4-thiodiazoles are generally formed when amidines or alkyl-S-isothioureas, expediently in the form of their salts, with perchloromethyl mercaptan (Org. Syntheses, Coll. Vol. 1, 506 ) reacts in the presence of alkali: The reaction is carried out in such a way that the required amount of sodium hydroxide solution is gradually added with stirring and cooling to the mixture of aqueous amidine salt solution and perchloromethyl mercaptan to which an emulsifier or an organic inert solvent has been added.

The separation of the desired products, which in 5o to 7o ° / aiger The resulting yield can be done by filtration or distillation. It deals are colorless, liquid or crystalline, storage-stable substances that, like was found to be a large one because of the high reactivity of its halogen Number of conversions, in particular to link the thiodiazole radical with others organic or inorganic residues via oxygen, nitrogen, or sulfur Carbon bridges are capable.

The 5-chloro-i, 2, 4-thiodiazoles are used as intermediates for the Production of remedies, dyes and vulcanization aids suitable.

Example i 5-Chloro-3-methyl-i, 2, 4-thiodiazole 47 g of acetamidine hydrochloride (0.5 mol), 500 ml of methylene chloride and 83 g of perchloromethyl mercaptan (0.45 mol) are combined and with strong cooling and mechanical stirring with a solution of 100 g sodium hydroxide in 150 ml water added dropwise (temp. below - 8 °). The sodium chloride is filtered off with suction, the phases are separated, the water layer is shaken out with more methylene chloride and the combined solutions are dried over sodium sulfate. After the solvent has been distilled off, a dark red oil remains which turns colorless at 45 ° / 18 mm. Yield: 60 ° / a. F. - i8 °, Kp.zr 51 °, n '"s 152075.

Correspondingly, 5-chloro-3-ethyl-i is obtained from propionamidine hydrochloride, 2,4-thiodiazole: liquid, m.p. -18 °, b.p. "60 °, n2 1.5129; from benzamidine hydrochloride 5-chloro-3-phenyl-1, 2, 4-thiodiazole: needles, mp 52 °, bp 3 ° 15 °; from phenacetamidine hydrochloride 5-chloro-3-benzyl-i, 2, 4-thiodiazole: liquid, melting point 4 °, boiling point 3 123 °, no 1.59o4.

Example 2 5-chloro-3-methylmercapto-i, 2, 4-thiodiazole 69.5 g (0.5 mol) of S-methyl isotbiourea sulfate are dissolved in 300 ml of water, first with 93 g of perchloromethymcaptan (0 , 5 mol) and a little emulsifier, then slowly mixed with a solution of 80 g of sodium hydroxide in 160 ml of water with cooling and mechanical stirring. After the reaction has ended, 20 to 30 ml of a 25% ammonia solution (Perclilor methyl mercaptan which has not reacted to destroy it) is added to the reaction mixture, the mixture is neutralized after stirring for a short time and the whole is subjected to steam distillation.

The lower layer of the distillate is separated and after drying distilled in vacuo or solidified by cooling and then from little Recrystallized ethanol or petroleum ether. Yield: 50 to 55%. Leaflet, F. 3o °, bp i7 98 °.

Correspondingly, from S-ethyl isothiourea hydrobromide, the 5-chloro-3-ethylmercapto-1, 2, 4-tbiodiazole: liquid, mp -44 °, b.p. 13-16 °, d2 ° 1.35.

Claims (1)

PATENT CLAIM process for the production of 5-chloro-i, 2, 4-thiodiazoles, characterized in that perchlor-methylmercaptan with amidines or alkyl-S-isothioureas, preferably in the form of their salts, in the presence of alkali in solutions or aqueous Emulsion reacts with stirring and cooling, the alkali being added gradually will.